WEB MACHINE WITH TILTABLE WEB SHEET AND WEWING METHOD

Description

Technical Field

[0001] The present invention relates to a Jacquard type loom and the production of parts in composite material and more particularly the production by three-dimensional (3D) weaving of fibrous reinforcement structures for such parts. Previous technique

[0002] One application of the invention is the production of parts made of structural composite materials, that is, structural parts with fiber reinforcement densified by a matrix, such as parts made of organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC). Organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC) materials replace metallic parts in certain sections of turbomachinery. Their use contributes to optimizing aircraft performance, particularly by improving turbomachine efficiency and reducing the overall mass of the turbomachine, thereby significantly reducing harmful emissions (CO, CO2, NOx, etc.).

[0003] The invention relates more particularly to the control of the direction of juxtaposition of weft yarns in the columns of weft yarns during weaving.

[0004] There figure 1 schematically illustrates a Jacquard type loom 310 used for the production of fibrous textures or fabric obtained by multilayer weaving between a plurality of layers of warp yarns 330 and a plurality of layers of weft yarns 331.

[0005] As is known, the 310 loom is equipped with a Jacquard mechanism 3311 supported by a superstructure not shown in the figure 1 The loom 10 also includes a harness 320 consisting of a heddle board 321 and control wires or heddles 322, each heddle 322 being connected at one end to a control hook 12 of the Jacquard mechanism 311 and at the other end to one of the return springs 313 fixed to the frame 314 of the loom 310.

[0006] Each heddle 322 includes an eyelet 323 through which a warp thread 330 passes. The heddles 322 and their associated eyelet 323 undergo a substantially vertical oscillating motion, represented by the double arrow F, under the tensile forces exerted respectively by the control hooks 312 and the return springs 313. The heddles 322 allow certain warp threads 330 to be lifted, thus creating a sheaf 315, that is, an opening between the lower and upper layers of warp threads 330, allowing the introduction of weft threads 331 by means of a spear 341. The spear 341 is equipped at its end with a gripper 342 that grasps a weft thread 331 from a bobbin 340 and places it through the opening between the layers of warp threads 330 created by the sheaf 315, the weft thread 331 being cut at using a knife 343 after positioning himself in the crowd 315.

[0007] A reed 350, located upstream of the spool 341 in its resting position, is then folded down to compact the weft yarn(s) introduced into the sheaf 315. The spool 341 is then ready to pick up a new weft yarn 331 from the bobbin 40 and place it. A fibrous structure with a three-dimensional (3D) weave is thus progressively formed between the warp yarns 330 and the weft yarns 31.

[0008] If this type of loom allows for the creation of complex weaves, i.e. 3D, all the columns of weft threads are oriented at 90° with respect to a horizontal direction DH.

[0009] However, there is an advantage to being able to position the weft columns at an angle other than 90°, particularly for pre-positioning the wefts before shaping the fibrous structure or for defining specific mechanical properties in the final part.

[0010] US documents 2022 / 111606, EP 0 310 847 and US 3 425 549 describe looms for the three-dimensional weaving of a fibrous reinforcement for a part made of composite material. Description of the invention

[0011] To this end, the present invention proposes a Jacquard-type loom intended to produce a fibrous structure by three-dimensional weaving between a plurality of warp yarns and a plurality of weft yarns extending in a horizontal direction, the loom comprising a plurality of control yarns capable of moving the warp yarns in a vertical direction, at least one spear present downstream of the control yarns capable of pulling a weft yarn and a movable reed between a rest position upstream of the spear and a striking position of a pattern of the fibrous structure in a striking direction parallel to the horizontal direction,characterized in that the comb comprises at least two fixed parts forming an angle between them and in that the comb is mounted on the loom by means of a positioning mechanism capable at least of orienting the comb around an axis of rotation so as to adjust an angular position of said at least two fixed parts of the comb relative to a horizontal reference plane, the loom further comprising vertical translation means capable of moving the comb or the fiber structure along the vertical direction so as to move said comb or fiber upwards or downwards relative to the horizontal reference plane.

[0012] In the loom of the invention, the angle at which the reed strikes the warp can be adjusted to a value other than 90° relative to a horizontal reference plane. This makes it possible to weave columns of weft yarns in which the weft yarns are placed side by side in a direction of overlap that is not perpendicular to the horizontal reference plane. The inclination of the direction of overlap is controlled by selecting the angle at which the reed strikes the warp.

[0013] According to a particular feature of the loom of the invention, the angle formed between said at least two fixed parts is between 60° and 80°, more preferably an angle of about 70°.

[0014] The invention also relates to a method for three-dimensional, one-piece weaving of a fibrous structure between a plurality of layers of warp yarns and a plurality of layers of weft yarns, the weaving being carried out by a loom according to the invention, the warp yarns extending in a horizontal direction corresponding to the direction of advancement of said warp yarns, the weft yarns extending in a transverse direction, the weft yarns being woven in a plurality of columns spaced apart from each other in the horizontal direction, each column of weft yarns being positioned by the reed of the loom against the face of the fibrous structure, the weft yarns of each column of weft yarns being juxtaposed in the thickness of the fibrous structure in a determined direction of overlap, the method comprising weaving at least one portion with inclined weft columns in the fibrous structure,the weft threads of the weft thread columns of said at least one portion with inclined weft columns being juxtaposed along at least one first direction of superposition not perpendicular to a horizontal reference plane.

[0015] This forms a fibrous structure comprising one or more deployment portions in which the weft yarns in the weft yarn columns are juxtaposed along a superposition direction forming an angle with the horizontal direction other than 90°.

[0016] According to a particular feature of the process of the invention, the weft yarns of the weft yarn columns of said at least one portion with inclined weft columns are juxtaposed along different first and second directions of superposition.

[0017] This forms a portion of fibrous structure with columns of weft yarns exhibiting a broken shape.

[0018] According to another particular feature of the process of the invention, said at least one portion with inclined weft columns is linked by weaving to one or more adjacent portions of the fibrous structure, the weft yarns of the weft yarn columns of the adjacent portion(s) being juxtaposed along a superposition direction perpendicular to the horizontal direction.

[0019] The section(s) with inclined weft columns may correspond to one or more deployment sections that are folded during the shaping of the fibrous structure. Thus, after folding the section(s) with inclined weft columns, the angular variation resulting from the shear forces exerted on them during deployment causes the horizontal straightening of the weft yarn columns in these sections and prevents delamination in the fibrous structure at the inner radius.

[0020] According to another particular feature of the method of the invention, the first direction of superposition in said at least one portion with inclined frame columns forms an angle with the horizontal direction of between 60° and 80°, more preferably an angle of about 70°.

[0021] The invention also relates to a method for manufacturing a part made of composite material comprising: weaving a fibrous structure according to the weaving process according to the invention, shaping the fibrous structure so as to obtain a fibrous preform, densifying the fibrous preform by a matrix.

[0022] The invention further relates to a fibrous structure having a three-dimensional weave between a plurality of layers of warp yarns and a plurality of layers of weft yarns, the warp yarns extending in a horizontal direction, the weft yarns extending in a transverse direction, the structure comprising a plurality of columns of weft yarns spaced apart in the horizontal direction, the weft yarns of each column of weft yarns being juxtaposed in the thickness of the fibrous structure in a determined direction of superposition, the fibrous structure comprising at least one portion with inclined columns of weft yarns, the weft yarns of the columns of weft yarns of said at least one portion with inclined columns of weft yarns being juxtaposed in at least one first direction of superposition not perpendicular to the horizontal direction.

[0023] According to a particular feature of the fibrous structure of the invention, the weft yarns of the weft yarn columns of said at least one portion with inclined weft columns are juxtaposed along different first and second directions of superposition. The fibrous structure thus comprises one or more portions with weft yarn columns having a broken shape.

[0024] According to another particular feature of the fibrous structure of the invention, said at least one portion with inclined weft columns is linked by weaving to one or more adjacent portions of the fibrous structure, the weft yarns of the weft yarn columns of the adjacent portion(s) being juxtaposed along a superposition direction perpendicular to the horizontal direction.

[0025] According to another particular feature of the fibrous structure of the invention, the first direction of superposition in said at least one portion with inclined frame columns forms an angle with the horizontal direction of between 60° and 80°, more preferably an angle of about 70°.

[0026] The invention further relates to a part made of composite material comprising a fibrous reinforcement densified by a matrix characterized in that the fibrous reinforcement comprises a fibrous structure according to the invention. Brief description of the drawings

[0027] [ Fig. 1 ] There figure 1 is a schematic perspective view of a Jacquard-type loom according to the prior art, [ Fig. 2 ] There figure 2 is a schematic perspective view of a Jacquard-type loom according to one embodiment of the invention, [ Fig. 3 ] There figure 3 is a side view of the loom of the figure 2 showing the weaving of a portion of fibrous structure with columns of weft yarns perpendicular to a horizontal reference plane, [ Fig. 4 ] There figure 4 is a side view of the loom of the figure 2 showing the weaving of a portion of fibrous structure with columns of weft yarns inclined along a superposition direction, [ Fig. 5 ] There figure 5 is a side view of the loom of the figure 2 showing the weaving of a portion of fibrous structure with columns of weft yarns inclined along two different superposition directions, [ Fig. 6 ] There figure 6 is a side view of the loom of the figure 2 showing the weaving of a portion of fibrous structure with columns of weft yarns inclined along two different overlapping directions. Description of the implementation methods

[0028] The invention applies generally to Jacquard-type looms used, in particular, for producing fibrous structures or fabrics by three-dimensional (3D) weaving between layers of warp yarns and layers of weft yarns. The invention applies more specifically to the 3D weaving of fibrous structures with at least one portion of inclined weft columns, as explained in detail below. "Three-dimensional weaving" or "3D weaving" refers to a weaving method in which at least some of the weft yarns interlock warp yarns over several layers of warp yarns, or vice versa. An example of three-dimensional weaving is the so-called "interlock" weave. "Interlock" refers to a weave structure in which each layer of warp yarns interlocks several layers of weft yarns, with all the yarns in the same warp column having the same movement within the plane of the weave.The wires used here may include carbon fiber wires or ceramic fiber wires such as silicon carbide (SiC) fibers, the invention not being limited to these types of wires only.

[0029] There figure 2 illustrates a loom 100 according to an embodiment of the invention. The loom 100 is equipped with a Jacquard mechanism 101 supported by a superstructure not shown in the figure 3 The loom 100 also includes a harness 110 consisting of a heddle board 111 and control threads or heddles 113, each heddle 113 being connected at one end to a control hook 102 of the Jacquard mechanism 101 and at the other end to one of the return springs 105 fixed to the frame 103 of the loom 100. Each heddle 113 includes an eyelet 114 through which a warp thread 203 passes. The warp threads 201 are arranged in the harness 110 of the loom in a plurality of layers and columns which are, as explained below, manipulated by the loom to allow the insertion of weft threads 204 according to the weaving pattern(s) programmed into the loom. The warp threads 203 extend in a horizontal direction DH corresponding to their direction of travel during weaving.The weft yarns 204 are inserted between the warp yarns in columns along a transverse direction DT perpendicular to the horizontal direction DH. In order to allow the introduction of each column of weft yarns during the weaving of the fibrous structure, a warp yarn calling system (not shown in the figure). figure 2 ) is associated with the loom. This system, placed downstream of the loom, has the role of holding all the warp threads together in a bridling device and of allowing the advancement of the warp threads a determined distance after the insertion of each weft column.

[0030] The rails 113 and their associated eyelet 114 extend into a zone Z in which the rails 113 and eyelets 114 are animated by a substantially vertical oscillating motion represented by the double arrow F. During the creation of a crowd, as illustrated on the figure 2 , part of the heddles 113 are subjected to tensile forces exerted by the control hooks 102. In this configuration, the heddles 113 allow some warp threads 203 to be lifted and thus create a sheaf 104 allowing the passage of a lance 120 for the introduction of weft threads 204.

[0031] The lance 120, located downstream of the rails 113, is composed of a rod 121, one end of which is connected to an actuation system (not shown on the figure 2 ) allowing the rod 121 to move back and forth along the double direction D 121. The other end of the rod 121 is equipped with a gripper 122 which, after passing through the spool 104 during the forward movement of the rod 121, grasps a weft yarn 204 stored on a bobbin 130 to unwind it into the spool 104 during the return movement of the rod 121. The weft yarn 204 thus placed inside the spool 104 is cut in the vicinity of the bobbin 130 by a knife 140 and released at its other end by the gripper 122.

[0032] A reed 150, positioned upstream of the spool 120 in its resting position, is then folded down to compress the weft yarn(s) introduced into the sheaf 104 against the rib 205 of a fibrous structure 200. The spool 120 is then ready to pick up a new weft yarn 204 from the bobbin 130 and place it either back into the sheaf 104 or into a different sheaf, depending on the defined weave pattern. A fibrous structure 200 is thus progressively formed, exhibiting a 3D weave between the warp yarns 203 and the weft yarns 204.

[0033] According to the invention, the direction of overlap of the weft threads in each weft column is adjusted with the reed 150. Indeed, the angle at which the reed strikes the weft threads against the weft 205 of the fibrous structure 200 determines the direction of overlap of the weft threads in each weft column. To this end, in the present invention, the loom is equipped with a reed comprising at least two fixed parts forming an angle with each other, the reed being orientable in order to adjust its striking angle on the weft of the woven fibrous structure according to the desired direction of overlap in each weft column. The striking direction of the reed is parallel to the horizontal direction DH.The vertical position of the comb relative to the fibrous structure is also adjustable in order to position one or more fixed parts of the comb opposite the shape of the fibrous structure.

[0034] In the example described here, the comb 150 successively comprises first, second and third fixed parts 151, 152 and 153 forming an angle between them, the first and second fixed parts 151 and 152 forming an angle α 1 between them while the second and third fixed parts 152 and 153 form an angle α 2 between them ( figures 3 à 6 ).

[0035] The reed 150 is mounted on the loom by means of a positioning mechanism 170 attached for example to the frame 103. The mechanism 170 includes an angular adjustment device 171 comprising a rotation axis or ball joint 1710 to which is connected the lower end of the fixed part 151 of the reed.

[0036] The loom according to the invention also includes means for vertically translating the reed or the loom of the fibrous structure.

[0037] Regarding the vertical translation of the reed, the positioning mechanism 170 further includes a vertical translation device 172 on which the angular adjustment device 171 is mounted. The vertical translation device 172 is fixed to the frame 103 of the loom. The device 172 allows the reed 150 to be moved up or down relative to a horizontal reference plane PH. The horizontal reference plane PH corresponds to the mid-section of the weave 205 of the fiber structure along the vertical direction DV.

[0038] Regarding the vertical translation of the fiber structure's weave, the loom further comprises a holding device 160 including a lower jaw 161 and an upper jaw 162, each connected to an actuation means (not shown in the figure 2 ) which is capable of holding the woven structure 200, on the one hand, and of moving the jaws 160 and 161 along the vertical direction DV. The holding device 160 allows the rib 205 of the woven structure to be moved along the vertical direction DV upwards or downwards relative to the horizontal reference plane PH.

[0039] The positioning mechanism 170 is thus able to orient the comb around the axis of rotation 1710 so as to adjust an angular position of the first, second and third fixed parts 151, 152 and 153 of the comb 150 relative to the horizontal reference plane PH and to move the comb or the fiber structure along the vertical direction DV so as to move said comb up or down relative to the horizontal reference plane PH.

[0040] The comb 150 and / or the positioning mechanism 160 are mounted on a striking mechanism (not shown on the figure 2 ) allowing the 205 fracture of the fibrous structure to be struck along a striking direction DF parallel to the horizontal direction DH.

[0041] Thus, during the weaving of each portion of a fibrous structure, the angular and vertical positions of the reed relative to the weave of the fibrous structure are adjusted so that one or more fixed parts of the reed strike the weave of the fibrous structure at one or more determined angles.

[0042] We now describe several examples of 3D weaving with the loom 100 according to the invention.

[0043] There figure 3 This shows the weaving of a portion 10 of a fibrous structure by 3D weaving between a plurality of warp yarn layers 11 and a plurality of weft yarn layers 12. The weft yarns are woven in the portion 10 in a plurality of columns C T12 spaced from each other along the horizontal direction DH. The weft yarns of each column of weft yarns C T12 are juxtaposed in the thickness of the portion 10 of the fibrous structure along a determined overlapping direction D S12 perpendicular to the horizontal reference plane PH.

[0044] During the weaving of portion 10, the reed 150 is oriented around its axis of rotation 1710 so that the second fixed part 152 is perpendicular to the horizontal reference plane PH. The reed 150 or the weft 15 of the fibrous structure portion 10 is positioned along the vertical direction DV so that the second fixed part 152 is opposite the weft 15. Thus, with each strike of the reed 150 on the weft 15 along the strike direction DF, the weft yarns of portion 10 are juxtaposed in each weft yarn column along the overlapping direction DS10, which is perpendicular to the horizontal direction DH.

[0045] There figure 4 This shows the weaving of a portion 20 of a fibrous structure by 3D weaving between a plurality of warp yarn layers 21 and a plurality of weft yarn layers 22. The weft yarns are woven in the portion 20 in a plurality of columns CT22 spaced from each other along the horizontal direction DH. The weft yarns 22 of each column of weft yarns CT22 of the portion 20 are juxtaposed against the rib 25 of the portion 20 of fibrous structure along a superposition direction DS22 not perpendicular to the horizontal reference plane PH.

[0046] During the weaving of the fibrous structure portion 20, the reed 150 is oriented around its axis of rotation 1710 so that the third fixed part 153 forms an angle β22 with the horizontal reference plane PH which is greater than 90°. The reed 150 or the weft 25 is positioned along the vertical direction DV so that the third fixed part 153 is opposite the weft 25. Thus, with each strike of the reed 150 along the strike direction DF, the weft yarns of the portion 20 are juxtaposed in each weft yarn column along the overlapping direction D S22 forming the angle β22 with the horizontal reference plane PH.

[0047] There figure 5 This shows the weaving of a portion 30 of fibrous structure by 3D weaving between a plurality of warp yarn layers 31 and a plurality of weft yarn layers 32. The weft yarns are woven in the portion 30 in a plurality of columns C T32 spaced from each other along the horizontal direction DH. The weft yarns 32 of each column of weft yarns C T32 of the portion 30 are juxtaposed against the weave 35 of the portion 30 of fibrous structure along a first superposition direction D S320 not perpendicular to the horizontal reference plane PH and a second superposition direction D S321 perpendicular to the horizontal reference plane PH.

[0048] During the weaving of the fibrous structure portion 30, the reed 150 is oriented around its axis of rotation 1710 so that the first fixed part 151 forms an angle β 320 with the horizontal reference plane PH that is greater than 90°, and so that the second fixed part 152 forms an angle of 90° with the horizontal reference plane PH. The reed 150 or the weft 35 is positioned along the vertical direction DV so that a portion of the first fixed part 151 is opposite a lower portion of the weft 35, and so that a portion of the second fixed part 152 is opposite an upper portion of the weft 35.Thus, with each strike of the reed 150 along the strike direction DF, the weft yarns of portion 30 are juxtaposed in each weft yarn column along the first overlap direction DS320, forming the angle β320 with the horizontal reference plane PH, and along the second overlap direction DS321, perpendicular to the horizontal reference plane PH. This results in a portion of the fibrous structure with weft yarn columns exhibiting a broken shape.

[0049] There figure 6This shows the weaving of a portion 40 of fibrous structure by 3D weaving between a plurality of warp yarn layers 41 and a plurality of weft yarn layers 42. The weft yarns are woven in the portion 40 in a plurality of columns C T42 spaced from each other along the horizontal direction DH. The weft yarns 42 of each column of weft yarns C T42 of the portion 40 are juxtaposed against the rib 45 of the portion 40 of fibrous structure along a first superposition direction D S420 not perpendicular to the horizontal reference plane PH and a second superposition direction D S421 perpendicular to the horizontal reference plane PH.

[0050] During the weaving of the fibrous structure portion 40, the reed 150 is oriented around its axis of rotation 1710 so that the second fixed part 152 forms an angle β 420 with the horizontal reference plane PH that is less than 90°, and so that the third fixed part 153 forms an angle of 90° with the horizontal reference plane PH. The reed 150 or the weft 45 is positioned along the vertical direction DV so that a portion of the second fixed part 152 is opposite a lower portion of the weft 45, and so that a portion of the third fixed part 153 is opposite an upper portion of the weft 45.Thus, with each strike of the reed 150 along the strike direction DF, the weft yarns of the portion 40 are juxtaposed in each weft yarn column along the first overlap direction D S420, forming the angle β4 20 with the horizontal reference plane PH, and along the second overlap direction D S421, perpendicular to the horizontal reference plane PH. This results in a portion of the fibrous structure with weft yarn columns exhibiting a broken shape.

[0051] A fibrous structure according to the invention, that is, comprising a portion with columns of inclined or broken wefts as described above, can be used as fibrous reinforcement for a composite part. To this end, after possible shaping of the fibrous structure, the structure or fibrous preform is densified to form a composite part. The densification of the fibrous preform intended to form the fibrous reinforcement of the part to be manufactured consists of filling the porosity of the preform, in all or part of its volume, with the material constituting the matrix. This densification can be carried out in a manner known per se, using the liquid process (CVL), the gas process (CVI), the ceramic filler injection process (Slurry Cast), the silicon alloy impregnation process (MI or RMI), or a combination of one or more of these processes.

[0052] The liquid process involves impregnating the preform with a liquid composition containing a precursor of the matrix material. The precursor is usually a polymer, such as a high-performance epoxy resin, possibly diluted in a solvent. The preform is placed in a mold that can be sealed tightly, with a cavity shaped like the final molded blade. The mold is then closed, and the liquid matrix precursor (e.g., a resin) is injected into the entire cavity to impregnate all the fibrous material of the preform.

[0053] The transformation of the precursor into a matrix, namely its polymerization, is carried out by heat treatment, generally by heating the mold, after removal of any solvent and crosslinking of the polymer, the preform always being kept in the mold having a shape corresponding to that of the part to be produced.

[0054] In the case of carbon or ceramic matrix formation, heat treatment consists of pyrolyzing the precursor to transform the matrix into a carbon or ceramic matrix, depending on the precursor used and the pyrolysis conditions. For example, liquid ceramic precursors, particularly SiC or SiCN, can be polycarbosilane (PCS), polytitanocarbosilane (PTCS), or polysilazane (PSZ) type resins, while liquid carbon precursors can be resins with relatively high coke content, such as phenolic resins. Several consecutive cycles, from impregnation to heat treatment, can be carried out to achieve the desired degree of densification.

[0055] In the case of organic matrix formation, the densification of the fibrous preform can be achieved using the well-known resin transfer molding (RTM) process. According to the RTM process, the fibrous preform is placed in a mold with the external shape of the part to be produced. A thermosetting resin is injected into the internal space of the mold containing the fibrous preform. A pressure gradient is generally established within this internal space between the resin injection point and the resin discharge ports to control and optimize the resin impregnation of the preform.

[0056] The densification of the preform can also be achieved by polymer impregnation and pyrolysis (PIP), or by impregnation with a slurry (“slurry cast”), containing for example SiC and organic binders, followed by infiltration with liquid silicon (“melt infiltration”).

[0057] The densification of the fibrous preform can also be achieved, using a known method, via gaseous chemical vapor deposition (CVI) of the matrix. The fibrous preform corresponding to the fiber reinforcement of the blade to be produced is placed in a furnace into which a reactive gaseous phase is introduced. The pressure and temperature within the furnace, as well as the composition of the gaseous phase, are chosen to allow the diffusion of the gaseous phase within the porosity of the preform. This diffusion forms the matrix by depositing, at the core of the material in contact with the fibers, a solid material resulting from the decomposition of a component of the gaseous phase or from a reaction between several components. This contrasts with the pressure and temperature conditions specific to CVD (Chemical Vapor Deposition) processes, which lead exclusively to deposition on the surface of the material.

[0058] The formation of a SiC matrix can be obtained with methyltrichlorosilane (MTS) giving SiC by decomposition of MTS while a carbon matrix can be obtained with hydrocarbon gases such as methane and / or propane giving carbon by cracking.

[0059] A densification combining liquid and gaseous pathways can also be used to facilitate implementation, limit costs and manufacturing cycles while obtaining satisfactory characteristics for the intended use.

[0060] The densification processes described above make it possible to produce, from the fibrous structure of the invention, primarily parts made of organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC). Organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC) materials replace metallic parts in certain sections of turbomachinery. Their use contributes to optimizing aircraft performance, particularly by improving turbomachine efficiency and reducing the overall mass of the turbomachine, thereby significantly reducing harmful emissions (CO, CO2, NOx, etc.).

[0061] After densification, a part made of composite material is obtained.

[0062] The fibrous structure and its manufacturing process according to the present invention can in particular be used to produce turbine ring sectors, stiffeners, fixed or moving turbomachine blades.

Claims

1. A Jacquard type loom (100) intended to produce a fibrous structure (200) by three-dimensional weaving between a plurality of warp yarns (203) and a plurality of weft yarns (204) extending in a horizontal direction (DH), the loom comprising a plurality of control yarns (113) able to move the warp yarns in a vertical direction (DV), at least one rapier (120) present downstream of the control yarns (113) able to pull a weft yarn (204) and a reed (150) movable between a rest position upstream of the rapier and a beat-up position of a fell of the fibrous structure in a beat-up direction (DF) parallel to the horizontal direction, characterized in that the reed (150) comprises at least two stationary portions (151, 152) forming an angle (α1) therebetween and in that the reed is mounted on the loom by means of a positioning mechanism (170) able to at least orient the reed about an axis of rotation (1710) so as to adjust an angular position of said at least two stationary portions of the reed relative to a horizontal reference plane (PH), the loom further comprising vertical translation means (172, 160) able to move the reed or the fell of the fibrous structure in the vertical direction (DV) so as to move said reed or said fell upwards or downwards relative to the horizontal reference plane (PH).

2. The loom according to claim 1, wherein the angle (α1 formed between said at least two stationary portions is comprised between 60° and 80°.

3. A method for three-dimensional weaving in a single piece of a fibrous structure between a plurality of layers of warp yarns and a plurality of layers of weft yarns, the weaving being performed by a loom (100) according to claim 1 or 2, the warp yarns (21) extending in a horizontal direction (DH) corresponding to the direction of advance of said warp yarns, the weft yarns (22) extending in a transverse direction (DT), the weft yarns being woven in a plurality of columns (CT22) spaced from each other in the horizontal direction (DH), each column of weft yarns being positioned by the reed (150) of the loom (100) against the fell (25) of the fibrous structure, the weft yarns of each column of weft yarns being juxtaposed in the thickness of the fibrous structure in a determined layering direction, the method comprising the weaving of at least one section with inclined weft columns (20) in the fibrous structure, the weft yarns of the column of weft yarns (CT22) of said at least one section with inclined weft columns being juxtaposed in at least one first layering direction (DS22) not perpendicular to a horizontal reference plane (PH).

4. The method according to claim 3, wherein the weft yarns (32) of the columns of weft yarns (CT32) of said at least one section with inclined weft columns are juxtaposed in different first and second layering directions (DS320, DS321).

5. The method according to claim 3, wherein said at least one section with inclined weft columns (20) is interlinked by weaving to one or more adjacent sections of the fibrous structure, the weft yarns of the columns of weft yarns of the adjacent section(s) being juxtaposed in a layering direction perpendicular to the horizontal direction (DH).

6. The method according to any one of claims 3 to 5, wherein the first layering direction (DS22) in said at least one section with inclined weft columns (20) forms an angle with the horizontal direction comprised between 60° and 80°.

7. A method for manufacturing a composite material part comprising: - weaving a fibrous structure in accordance with the weaving method according to any one of claims 3 to 6, - shaping the fibrous structure so as to obtain a fibrous preform, - densifying the fibrous preform by a matrix.

8. A fibrous structure obtained in accordance with the three-dimensional weaving method according to claim 3, the fibrous structure having a three-dimensional weaving between a plurality of layers of warp yarns (21) and a plurality of layers of weft yarns (22), the warp yarns extending in a horizontal direction (DH), the weft yarns extending in a transverse direction (DT), the structure comprising a plurality of columns of weft yarns spaced from each other in the horizontal direction, the weft yarns of each column of weft yarns being juxtaposed in the thickness of the fibrous structure in a determined layering direction, the fibrous structure comprising at least one section with inclined weft columns (20), the weft yarns of the columns of weft yarns (CT22) of said at least one section with inclined weft columns being juxtaposed in at least one first layering direction (DS22) not perpendicular to the horizontal direction.

9. The structure according to claim 8, wherein the weft yarns (32) of the columns of weft yarns (CT32) of said at least one section with inclined weft columns (30) are juxtaposed in different first and second layering directions (DS320, DS321).

10. The structure according to claim 8, wherein said at least one section with inclined weft columns (20) is interlinked by weaving to one or more adjacent sections of the fibrous structure, the weft yarns of the columns of weft yarns of the adjacent section(s) being juxtaposed in a layering direction perpendicular to the horizontal direction.

11. The structure according to any one of claims 8 to 10, wherein the first layering direction (DS22) in said at least one section with inclined weft columns (20) forms an angle (β22) with the horizontal direction comprised between 60° and 80°.

12. A composite material part comprising a fibrous reinforcement densified by a matrix, characterized in that the fibrous reinforcement comprises a fibrous structure according to any one of claims 8 to 11.